Policy control architecture has been defined by 3rd Generation Partnership Project (3GPP). Policy elements can maintain information on active packet connections of users and about packet gateways via which the packet connections traverse.
In the future, 3GPP mobile networks can interface fixed broadband networks, defined for example by broadband forum (BBF). Policy and charging control is an important and integral part of the interworking. A UE connected to a fixed broadband access can use services that are offered by the 3GPP mobile network, i.e. the user traffic can be routed from the broadband access to the 3GPP packet core network. Both the fixed broadband network and the 3GPP network can have policy control and enforcement functions on the user plane.
Also, A UE connected to a 3GPP access can uses services that are offered by the fixed broadband network, i.e. the user traffic is routed from the 3GPP access to the fixed broadband packet core network. Again, both the 3GPP and fixed broadband network can have policy control and enforcement functions on the user plane.
In one architectural scenario a 3GPP Femto Home Node-B (H(e)NB) can be connected via a fixed broadband access to a 3GPP mobile core network. In this scenario an IP security tunnel is established between the home Node B and the security gateway (SeGW) in the mobile core network. Three different policy control/decision entities may be involved in a user session: Broadband policy control function (BPCF) in the broadband access, visited PCRF (V-PCRF) in the visited mobile network in a roaming case and home PCRF (H-PCRF) in the home mobile network.
Currently it is open how the different policy control entities (e.g. V-PCRF and H-PCRF) can find each other and how the related control sessions (S9, S9*, Gxc) can be established.